Menthol cigarette

ABSTRACT

Cigarettes are provided which contain a filtering system and flavorants encapsulated with polyvinyl acetate, wherein deactivation of a sorbent by the flavorant is reduced through the encapsulation of the flavorant within the polyvinyl acetate. A preferred flavorant is menthol. The encapsulated flavorants are prepared by mixing at least one flavorant with polyvinyl acetate and a solvent, such as ethanol, and forming the encapsulated flavorants. Methods of making cigarettes and smoking the articles are also provided.

BACKGROUND

Flavorants are frequently added to tobacco products to achieve desirableorganoleptic sensations. One of the common flavorants is menthol.Menthol is a volatile compound and tends to vaporize (volatilize) andgradually escape from the tobacco product during storage.

Various sorbent materials have been employed as additives in tobaccoproducts to remove selected constituents of tobacco smoke. The morecommon additives include activated carbons, molecular sieves, zeolitesand mixtures thereof.

Activated carbons are useful sorbent materials and have a largeabsorbent capacity. However, while activated carbons are effective inremoving targeted constituents from tobacco smoke, they lack selectivityand also absorb volatile flavorants such as menthol when present intobacco products.

Accordingly, there is interest in providing flavorants such as mentholin tobacco products containing sorbent materials such as activatedcarbons, molecular sieves, and zeolites, in a form which protects theflavorants from volatilization, deterioration and absorption by thesorbent material while enabling the flavorant to be gradually releasedwhen the tobacco products are smoked.

SUMMARY

A cigarette is provided which contains a flavorant encapsulated withpolyvinyl acetate, where heat and/or moisture are used to release theflavorant from the polyvinyl acetate encapsulation into mainstream smokeduring smoking. Also provided is a method of improving taste attributesof cigarettes containing sorbent, such as activated carbon, by usingflavorant with reduced deactivation of the sorbent.

Also provided is a filter cigarette comprising a substantiallycylindrical tobacco rod, a substantially cylindrical filter rod and atipping paper circumscribing and joining the filter rod and the tobaccorod wherein the filter rod includes a flavorant encapsulated bypolyvinyl acetate; a method of making a cigarette; and a method oftreating mainstream tobacco smoke.

In one embodiment, a cigarette comprising tobacco, a filter, sorbent,and an encapsulated flavorant comprising a polyvinyl acetate matrix withmenthol flavorant bound within the matrix is provided.

A further embodiment provides a method of making a cigarette including asorbent in a filter thereof, comprising: incorporating an encapsulatedflavorant comprising a polyvinyl acetate matrix with menthol flavorantbound within the matrix in a component of the cigarette.

In yet another embodiment, a method of flavoring mainstream tobaccosmoke, comprising: retaining a flavorant (menthol) with a polyvinylacetate matrix and releasing menthol from the matrix while generatingmainstream smoke, said releasing step including an application of heatand/or moisture to the matrix is provided.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1( a)-(c) illustrate exemplary embodiment encapsulated products ina tobacco rod.

FIGS. 2( a)-(c) illustrate flavor bands according to exemplaryembodiments.

FIG. 3 illustrates flavor bands according to another exemplaryembodiment.

FIG. 4 illustrates a puff-by-puff delivery of benzene in exemplaryembodiments.

FIG. 5 illustrates a puff-by-puff delivery of acrolein in exemplaryembodiments.

FIG. 6 illustrates a puff-by-puff delivery of 1,3-butadiene in exemplaryembodiments.

FIG. 7 illustrates menthol retention of exemplary embodiments when thementhol to polyvinyl acetate ratio is varied.

FIG. 8 illustrates menthol retention of exemplary embodiments when thesolvent volume is varied.

FIG. 9 illustrates results from ThermoGravimetric Analyzer (TGA) testsof a polyvinyl acetate-menthol film compared to pure menthol showingretention of menthol compared to weight loss of the film.

FIG. 10 illustrates menthol retention based on aging of a solution.

DETAILED DESCRIPTION

Cigarettes are described which contain flavorants encapsulated withpolyvinyl acetate and a filtering system comprising at least onesorbent. Methods of making encapsulated flavorants, methods ofmanufacturing cigarettes and methods of treating smoke from thesearticles are also described.

The term “smoking article” includes cigarettes, pipes, cigars,cigarillos and the like.

The term “mainstream smoke” includes aerosol drawn through a smokingarticle to the mouth end of the smoking article.

The term “encapsulation” includes both encapsulation andmicro-encapsulation of one material by another material, whereinmicroencapsulation includes encapsulation on a micro-capsule size, i.e.,between less than 1 μm to over 2000 μm. For example, as used herein,encapsulation preferably includes forming a matrix of one materialwherein a second material is microencapsulated within the matrix of thefirst material. Likewise, “encapsulated flavorants” refers to flavorantswhich are encapsulated or microencapsulated, preferably with flavorantsin a polyvinyl acetate encapsulant matrix.

Any number of flavorants are suitable for encapsulation with polyvinylacetate. Menthol is the preferred flavorant. Other suitable flavorantsinclude mint, such as peppermint and spearmint, vanillin, chocolate,licorice, citrus and other fruit flavors, spice flavors, such ascinnamon, methyl salicylate, linalool, bergamot oil, geranium oil, lemonoil, ginger oil, tobacco flavors and other agents commonly used toimpart flavor and aroma to the mainstream smoke of tobacco products.Flavorants suitable for encapsulation are also discussed in commonlyassigned U.S. Pat. Nos. 5,301,693, 5,228,461, and 5,137,036, which arehereby incorporated by reference in their entireties.

In accordance with one embodiment, one or more encapsulated flavorantsare incorporated in a filter of a cigarette wherein the filter employedin the cigarette includes at least one sorbent (absorbent or adsorbent).The term “sorbent” as used herein refers to an adsorbent, an absorbent,or a substance that can function as both an adsorbent and an absorbent.The term “sorption” is intended to encompass interactions on the outersurface of sorbents such as activated carbon, molecular sieves, zeoliteand other like materials, as well as interactions within the pores andchannels thereof.

Preferable sorbents include various forms of activated carbon, molecularsieves, such as zeolites, and mixtures thereof. Activated forms ofcarbon have strong physical adsorption forces, and high volumes ofadsorbing porosity. The activated carbon could be manufactured by anysuitable technique. One technique is the carbonization of coconut husk,coal, wood, pitch, cellulose fibers, or polymer fibers, for example.Carbonization is preferably carried out at high temperatures, i.e.,200-800° C. in an inert atmosphere, followed by activation underoxidizing conditions. The activated carbon used in the cigarettes couldbe in the form of monolithic shapes, granules, beads, powders or fibers.If desired, the activated carbon can be incorporated in another materialsuch as paper.

Activated carbon may include a distribution of micropores, mesopores andmacropores. The term “microporous” generally refers to such materialshaving pore sizes of about 20 Å or less while the term “mesoporous”generally refers to such materials with pore sizes of about 20 to 500 Å.The term “macroporous” refers to pore sizes above 500 Å. The relativeamounts of micropores, mesopores and macropores can be pre-selectedrelative to the selected constituents from mainstream tobacco smoke thatare to be targeted and removed. Thus, the pore sizes and poredistribution can be adjusted accordingly as needed for a certainapplication.

Another material which may be used as a sorbent in the filter system ofthe cigarette is a molecular sieve zeolite. The term “molecular sieve”as used herein refers to a porous structure composed of an inorganicsilicate material. Zeolites have channels or pores of uniform, molecularsized dimensions. There are many known unique zeolite structures havingdifferent sized and shaped channels or pores. The size and shape of thechannels or pores can significantly affect the properties of thesematerials with regard to adsorption and separation characteristics.Zeolites can be used to separate molecules in the channels or pores,and/or by differences in strength of sorption. By using one or morezeolites having channels or pores larger than selected constituents ofmainstream smoke, only selected molecules that are small enough to passthrough the pores of the molecular sieve material are able to enter thecavities and become sorbed by the zeolite.

Microporous, mesoporous and/or macroporous molecular sieves may be usedas the sorbent. They are selected for use in a filter system based onthe particular constituent(s) to be removed from the mainstream smoke.Zeolite-type molecular sieves which are useful in the cigarettes includecrystalline aluminosilicates, silicoaluminophosphates (AIPO/SAPO) andmesoporous molecular sieves such as MCM-41, MCM-48 and SBA-15. These arepreferably granular materials. This family of materials contains regulararrays of uniformly-sized channels and tunable internal active sites,and admits molecules below a certain size into their internal spacewhich makes them useful as catalysts and absorbents where selectivity isdesired.

The sorbent can be incorporated in one or more locations of thecigarette. For example, the sorbent can be placed in the passageway of atubular free-flow filter component, in the material of a filtercomponent, and/or in a void space of a filter. The sorbent canadditionally or alternatively be incorporated in a tobacco material orwrapper of a cigarette.

The filter may comprise a sorbent in oriented or non-oriented fibers anda sleeve, such as paper, surrounding the fibers. The sorbent can be, forexample, one or more of activated carbon, zeolite, and other molecularsieves located in fibrous forms. Sorbent mixtures can provide differentfiltration characteristics to achieve a targeted filtered mainstreamsmoke composition.

Alternatively, the sorbent can be composed of one or more sorbentmaterials, such as carbon, silica, zeolite and the like, impregnated inmicro-cavity fibers, such as TRIAD™ micro-cavity fiber available fromHoneywell International of Morristown, N.J. The fibers may be shapedmicro-cavity fibers impregnated with particles of one or more sorbentmaterials. See commonly assigned U.S. Pat. Nos. 6,584,979, 6,772,768 and6,779,528 which are hereby incorporated by reference in their entirety.

In another embodiment, the fibers may be bundles of non-continuousfibers, which are preferably oriented in the filter along the directionof mainstream smoke flow through a cigarette.

Sorbent containing filter rods can be formed, for example, by stretchinga bundle of non-crimped sorbent fiber material, preferably having acontrolled total and per filament denier, through a pre-formed orin-situ formed sleeve during the filter making process. The formedfilter rod can be separated into filter plugs by cutting to a desiredlength. For example, the filter plugs can have a length of from about 5mm to about 30 mm.

Sorbent can be incorporated in a cigarette filter at one or more desiredlocations. In a preferred embodiment, a sorbent segment is combined witha free-flow filter. The sorbent can be in contact with (i.e., abut) afree-flow filter positioned between the free-flow filter and amouthpiece filter plug or in contact with (i.e., abut) a mouthpiecefilter plug. The sorbent segment preferably has a diameter substantiallyequal to that of the outer diameter of a free-flow filter to minimizeby-pass of smoke during the filtration process.

Fibrous sorbent containing filter segments preferably have a high loftwith a suitable packing density and fiber length such that parallelpathways are created between fibers. Such structure can effectivelyremove selected gas-phase constituents, such as formaldehyde and/oracrolein, while preferably removing only a minimal amount of particulatematter from the smoke, thereby achieving a significant reduction of theselected gas-phase constituents, while not significantly affecting thetotal particulate matter (TPM) in the tobacco smoke. A low packingdensity and a short fiber length are preferred to achieve suchfiltration performance.

The amount of sorbent used in preferred embodiments of the cigarettedepends on the type of gas-phase constituents in the tobacco smoke andthe type of constituents that is desired to be removed from the tobaccosmoke.

When sorbents and flavorants are used in cigarettes, flavorants candeactivate sorbents when the flavorants are sorbed by the sorbents.Thus, to reduce the level of deactivation of sorbent, flavorants arepreferably protected from sorption by the sorbent by encapsulation.Through encapsulation, the interaction between the sorbent andflavorant, as well as the resulting sorption of the flavorant canthereby be reduced.

The encapsulated flavorant can be located at various parts of thecigarette to provide flavorant in the cigarette and reduce deactivationof sorbents. In one embodiment, the encapsulated flavorant may be in theform of beads located in tobacco filler. By using beads, a controlledrelease of the flavorant in the cigarette during puff cycles can beachieved. The beads preferably comprise polyvinyl acetate encapsulatingat least one flavorant, wherein heat and/or moisture supplied to theencapsulated flavorant during the smoking of the cigarette release theflavorant from the encapsulant. Other materials to improvecharacteristics of the encapsulating material or enhance its stabilitycan optionally be added, such as filler.

In an exemplary embodiment, beads of encapsulated additive can beprovided which have a substantially homogenous composition in whichflavorant is substantially uniformly distributed through the beads. Bysuch structure, the flavoring can be released from the beads in auniform manner during smoking.

Also, by encapsulating the flavorant, the encapsulated flavorant isprotected from exposure to the atmosphere (i.e., ambient air, inside apackage) and sorbents in a cigarette such as a cigarette. Thus, releaseand/or migration of the flavorant are minimal until the encapsulatedflavorant is exposed to increased moisture or heat. While not wishing tobe bound by theory, it is believed that increased moisture, as well asincreased temperature causes the polyvinyl acetate matrix encapsulatingthe flavorant to expand the polyvinyl acetate matrix, thus creatingpathways out from the polyvinyl acetate matrix and allowing forflavorant to escape.

For example, the polyvinyl acetate matrix encapsulated flavorant can beapplied to a filter of a cigarette, wherein moisture and heat fromcontact with a user's mouth can release the flavorant. As anotherexample, temperatures between 50° C. and 900° C., or between 100° C. and800° C. (e.g., above 25, 50, 100, 200, 300, 400, 500, 600, 700, 800° C.)can be applied to an encapsulated flavorant to expand an encapsulatingpolyvinyl acetate matrix, which in turn can cause release of flavorantfrom the encapsulating polyvinyl acetate matrix.

Consequently, unintentional release of the flavorant or interactionbetween the flavorant and sorbent can be reduced by encapsulating theflavorants. Also intentional release of the flavorant can be achievedthrough elevated moisture levels or elevated temperatures, which areavailable in a smoked cigarette. Therefore encapsulating flavorantwithin a polyvinyl acetate matrix allows for improved flavorant deliveryduring increased temperature and/or moisture levels, especially insorbent containing cigarettes.

The encapsulated flavorant can have any desired shape, including regularor irregular shapes, including round, square, rectangular, oval, otherpolygonal shapes, cylindrical, fibrous, and the like. Beads can havevarious sizes. Preferably, the beads are microbeads having a maximumparticle size of less than about 25 μm, and more preferably less thanabout 1 μm. Decreasing the size of the beads can provide a morehomogenous and controlled release of flavoring by providing increasedsurface area of the beads.

The encapsulated products can be manufactured by any suitable processthat produces articles having the desired structure, composition, andsize. For example, the encapsulated products can be manufactured byextrusion, spray drying, coating, or other suitable processes. In apreferred embodiment, the encapsulated products are prepared by forminga solution, dispersion or emulsion containing polyvinyl acetate,flavoring and optional flavorants and drying to obtain a shapedencapsulant.

While not wishing to be bound by theory, it is believed thatencapsulation of the flavorant by the polyvinyl acetate is based on theprinciple of surface segregation. It is believed that the polyvinylacetate forms a matrix with a surface portion of the encapsulatedflavorant including a higher ratio of polyvinyl acetate to encapsulantthan an inner portion where the polyvinyl acetate is segregated towardthe surface and the flavorant is segregated away from the surface.

The encapsulated flavorants are preferably prepared by mixing one ormore flavorants in powder or liquid form, a volatile solvent andpolyvinyl acetate, then drying the resultant solution to remove thesolvent and bind the flavorant to within a matrix formed by thepolyvinyl acetate. The product recovered is a flavorant encapsulated bythe polyvinyl acetate matrix to retain the flavorant and bind theflavorant within the matrix. The encapsulated product can be in the formof a fiber, film, monolith, bead, powder or granule.

Preferred solvents include methanol or ethanol. The solvent ispreferably sufficiently volatile to be entirely removed in the productleaving polyvinyl acetate and flavorant alone. However, the solvent mayremain if desired.

The proportions of the components can be widely varied. The amount offlavorant, such as menthol, can be from about 1-90%, about 2-70% orabout 10-50% by weight based on 100 parts by weight of the polyvinylacetate. The amount of solvent is preferably sufficient to solubilizethe flavorant and polyvinyl acetate.

Preferably, a composite of flavorant and polyvinyl acetate is formed bycompounding, blending and/or dissolution of the flavorant and thepolyvinyl acetate in solvent. Preferably, heat and mechanical shearingare used to mix the flavorant and polyvinyl acetate.

Also preferably, one or more flavorants are dissolved and/or entrappedas a separated phase in a continuous matrix of the polyvinyl acetate.Thus, the composite would be a matrix of polyvinyl acetate withflavorant within the matrix. Therefore, upon exposure to heat and/ormoisture, barrier properties of the polyvinyl acetate can be reduced bya relaxation of the polyvinyl acetate matrix caused by the increase intemperature and/or moisture levels, thus allowing for the flavorant tobe released from the matrix.

For example, a process for preparing menthol/polyvinyl acetatecomposites can include mixing a solvent, such as alcohol, for exampleethanol, and polyvinyl acetate to form a solution. Next, a mentholflavorant can be added to the ethanol and polyvinyl acetate solution toprovide flavoring. Next, the ethanol solvent content can be reduced toincrease the concentration levels of menthol and polyvinyl acetate inthe solution. It is noted that while menthol is volatile and canevaporate, the mixture of the menthol with the polyvinyl acetate in thisexample reduces menthol evaporation due to the menthol being dispersedwithin the polyvinyl acetate, wherein the dispersion reduces the mentholevaporation rate. Next, the mixture can be formed into desired shapes,such as fibers, films, monoliths, beads, powders, and granules, whereinthe solvent can be vaporized to form a final composite material with thementhol encapsulated within a matrix of polyvinyl acetate. Reducing thesolvent content is optional and can provide increased flavor content inthe final composite material.

It is also noted that the relative amounts of menthol in polyvinylacetate provides for variations in final flavorant levels. For example,if approximately 37% menthol is provided, approximately 35% menthol canbe expected to be released upon use. On the other hand, a level ofmenthol in the mixture can exceed base encapsulation levels for theseexemplary methods of encapsulation and alternative encapsulationtechniques can be used.

An example of menthol levels exceeding base encapsulation levels forthese exemplary methods of encapsulation is if the starting amount ofmenthol in the mixture is higher than, for example, approximately 70%.At this level, the amount of menthol for encapsulation is believed toexceed the base encapsulation levels, as only about 23% of the mentholwas found to be encapsulated for this example. While not wishing to bebound by theory, the menthol appears to agglomerate at higher levels,such as 70% for this exemplary method, and the menthol does not appearto disperse in the polyvinyl acetate matrix above a certain menthollevel, in this example at levels around 70%, thus reducing mentholencapsulation levels.

However, it is noted that another exemplary method can be used toencapsulate higher menthol levels. For example, if the mixture with thehigh menthol starting level of 70%, as mentioned above, is aged byholding the menthol and polyvinyl acetate in solution for an extendedperiod of time, improved flavorant encapsulation and eventual releaseupon use can be observed. For example, if a mixture of 70% menthol,solvent and polyvinyl acetate is aged for approximately three months, acomposite material, which is formed from the aged solution, can showimproved menthol retention and encapsulation with an eventual releaselevel during smoking of up to 70% menthol. Therefore, by aging highlyconcentrated menthol/polyvinyl acetate mixtures, menthol levels of up to70% can be achieved for release.

Alternatively, rather than aging, it is noted that similar results forencapsulating higher levels of menthol can be achieved by reducing thesolvent content of a solution of menthol, solvent and polyvinyl acetate.For example, the solvent in the solution can be evaporated away toreduce solvent content. By reducing solvent content similarly highmenthol levels encapsulated appear to be at encapsulation levels similarto that of menthol subjected to aging. For example, a solution withreduced solvent content and high levels of menthol, such as 55% menthol,can be encapsulated by polyvinyl acetate and can lead to menthol levelsof about 55% encapsulation.

It can be seen that flavorants can be encapsulated and provided invarious physical forms which are stabilized and thus not subject to lossthrough volatilization, deterioration and/or sorption by activatedcarbon, zeolites or other sorbents present in the cigarette. Preferably,the encapsulated flavorant contains flavorant, polyvinyl acetate andoptional flavorants with no other materials present.

The cigarette preferably comprises an amount of the encapsulatedflavorant that provides a desired amount of the flavoring in thecigarette. In a preferred embodiment, the cigarette comprises, based onthe total weight of tobacco in the cigarette, up to about 20%, and morepreferably about 10% to about 15%, of the encapsulated flavorant. Forexample, a cigarette containing 100 mg of tobacco preferably contains upto about 20 mg of encapsulated flavorant.

In a preferred embodiment, the encapsulated flavorant is disposed in atleast one location in a cigarette that reaches at least a minimumtemperature at which the flavoring is released from a polyvinyl acetateencapsulant during smoking. For example, the encapsulated flavorant canbe disposed in the tobacco or on a wrapper for burning, wherein acombination of heat and moisture can be used to release the flavorantfrom the polyvinyl acetate encapsulant.

In another preferred embodiment, the encapsulated flavorant is disposedin at least one location in a cigarette that is subjected to increasedmoisture during smoking wherein moisture from mainstream smoke or from asmoker's mouth can be used as the release mechanism for the flavorant.For example, the encapsulated flavorant can be disposed in a voiddownstream from a sorbent in a filter or on one more surfaces of a freeflow filter, wherein moisture from the mainstream smoke can release theflavorant from the encapsulant.

In another preferred embodiment, encapsulated flavorant is disposed intobacco rods by injecting the encapsulated flavorant in liquid form intotobacco rods. For example, the encapsulated flavorant can be formed asliquids, such as hot melt or solvent based liquids, of the encapsulatedflavorants for injection. Preferably, a liquid injection can be appliedto a center of a tobacco rod of a cigarette to wet the tobacco or fill acenter portion of the tobacco rod to provide encapsulated flavorant intoa tobacco rod. However, the injection can be at any position within thetobacco rod. For example, see FIG. 1( a) which illustrates a preferredembodiment tobacco rod 100 with encapsulated flavorants 150 injected inliquid form in a center portion of the tobacco rod 100 upstream from afilter 180.

In another preferred embodiment, the liquid encapsulated flavorant isdisposed in tobacco filler by spraying or coating the encapsulatedflavorant in liquid form onto the tobacco filler. For example, theencapsulated flavorant can be formed as hot melt or solvent basedsolutions (e.g., ethanol, polyvinyl acetate and menthol) of theencapsulated flavorants, as mentioned above, but in this embodiment, theliquid encapsulated flavorant is sprayed or coated on the tobaccofiller. Preferably for cigarettes, the sprayed or coated encapsulatedflavorants are applied uniformly to the tobacco filler prior to formingtobacco rods 100 in order to provide the encapsulated flavorant 160throughout the tobacco rod 100, as illustrated in FIG. 1( b).

In another preferred embodiment, solid encapsulated flavorant isdisposed in tobacco filler by mixing solid encapsulated flavorant intothe tobacco filler. Preferably, to increase the miscibility of the solidencapsulated flavorant, the solid encapsulated flavorant to be mixed isshredded, ground or otherwise mechanically processed into shredded film,ground powder, or otherwise smaller sized particles to increase themiscibility of the encapsulated flavorant into the filler. Preferably,the encapsulated flavorant 170 is mixed with the tobacco filler prior toor during the rod-making process thus allowing the encapsulatedflavorant 170 to be distributed throughout the tobacco rod 100, asillustrated in FIG. 1( c).

In another embodiment, the encapsulated flavorant can be present as afilm. The film can be provided by applying and drying a film formingmaterial with the flavorant therein, wherein the flavorant can beprovided as pre-encapsulated flavorant or non-encapsulated flavorantmixed within the film forming material. Preferably, the film formingmaterial comprises polyvinyl acetate film. Also preferably, theflavorant is menthol.

For example, beads of polyvinyl acetate pre-encapsulated menthol can bemixed within a polyvinyl acetate film forming material, then the mixturecan be applied to a cigarette as a film. Alternatively, anon-encapsulated liquid menthol can be mixed with a polyvinyl acetatefilm forming material, then the mixture can be applied to a cigarette asa film.

It is noted that the pre-encapsulated menthol can be pre-encapsulated byother adhesive, flavor-retaining polymeric materials, such as polyvinylalcohols, poly-acrylates, poly(ethylene) glycols, poly-glycolic acids,pectin, polysaccharides, poly-lactic acid, polyesters, polyethyleneoxides, poly epoxides, or the like prior to mixing the pre-encapsulatedmenthol with the film forming material.

In a preferred embodiment, the polyvinyl acetate film comprises byweight up to 20%, more preferably about 10% to about 15%, of flavorant,such as encapsulated or non-encapsulated menthol, and can be applied ona component of a cigarette. For example, the film can be applied to asurface of a filter, coated on a tobacco mat of a non-traditionalcigarette or coated on a paper wrapper of a cigarette. In a preferredembodiment, the film encapsulates menthol and optionally also mint.

Preferably, as mentioned above, the film-type encapsulated flavorantincludes an encapsulating polyvinyl acetate film forming material and atleast one flavorant. However, additional other materials can optionallybe added to improve the film-forming characteristics of theencapsulating polyvinyl acetate film forming material or enhance thepolyvinyl acetate film forming material's stability. In an exemplaryembodiment, the film has a substantially homogenous composition in whichflavorant is substantially uniformly distributed. The film encapsulatingmaterial provides a barrier to the release of the flavoring, wherein aneffective amount of flavoring is released as desired. For example, arelease of at least 0.01 mg/puff is desired from an exemplarytraditional cigarette, or a total weight of about 2 wt % of menthol ofthe total weight of a tobacco rod of a cigarette is desired prior tosmoking to allow for release upon smoking.

The film can be applied to one or more components of the cigarette, suchas an outer surface of a wrapper around a filter or an outer wrapper ofa cigarette, as a liquid coating, which is dried to a film. Thedimensions of the dried film are not limited. Preferably, the dried filmhas a maximum thickness of about 50 μm to about 150 μm, and morepreferably up to about 75 μm. The film can be manufactured by anysuitable process that produces a film having the desired structure,composition, and dimensions. For example, the film can be applied by acoating process, such as spray coating, a dipping process, electrostaticdeposition, printing wheel application, gravure printing, ink jetapplication, and the like. An emulsion, suspension or slurry comprisingthe polyvinyl acetate and flavorant, and optional additives is preparedand then applied as a coating to one or more selected surfaces of one ormore selected components of the cigarette. The coating is preferablydried to remove water and/or other solvents and form a solid film havingdesired dimensions. The drying can occur by evaporation or lowering ofthe temperature of the film in order to solidify and enhance theadherence of the film onto the selected surfaces.

In one embodiment, a film of polyvinyl acetate matrix encapsulated filmis formed on an outer surface of a wrapper around a cigarette filter,such as on a plug wrap or within a plug downstream from any sorbents. Byproviding the film in this location, the film can be exposed to elevatedheat and moisture from a smoker's mouth during smoking, as well as frommainstream smoke. As mentioned above, heat and moisture allows theencapsulated film to release at least a portion of the flavorant fromthe polyvinyl acetate matrix. Thus, by providing the film in a locationwith elevated moisture and/or temperature levels during use, theflavorant can be retained by entrapment within the polyvinyl acetatematrix during storage and released from the polyvinyl acetate matrixupon use.

In another embodiment, the film can be formed as flavor bands on theouter paper wrapper, where the flavor bands may be coated on an inner orouter side of an outer paper wrapper. Preferably, the number, width andposition of flavor bands are arranged in a way such that air can diffuseinto a tobacco rod to sustain combustion during static burn, but stillprovide flavorant to mainstream smoke. For example, as shown in FIG. 2(a), flavor bands 210 may be formed parallel to the burning direction ofthe tobacco rod 220, thus delivering flavor as a cigarette 200 issmoked. As illustrated in FIGS. 2( b) and 2(c), the flavor bands 210 maybe located on the inner side or the outer side of a cigarette paperwrapper 230. The flavor bands 210 may also be used with sorbents 240, asshown in FIG. 3.

The flavor bands may be formed before, during and/or after the formationof the tobacco rods by coating, printing, painting, spreading,extruding, dripping or casting the film on the paper surrounding thetobacco rods. Through using flavor bands, the flavor and any sorbenthave reduced interaction thus preserving the properties of each. Forexample, when flavor bands are placed on cigarettes, high mentholdelivery can be provided during smoking of cigarettes with activatedcarbon. Additionally, when using flavor bands with activated carboncontaining cigarettes, the activated carbon, as well as the flavor bandscan retain a desired level of their properties even after an extendedperiod of time in proximate relation to one another.

Carbon does not appear to interact with menthol flavor bands. Asillustrated in FIGS. 4-6, menthol flavor banded cigarettes B and C,which are also carbon containing, have similar benzene, acrolein and1,3-butadiene sorption compared to a non-menthol containing, carboncontaining control cigarettes (“control”), which absorb benzene,acrolein and 1,3-butadiene better than the non-carbon containingcigarette 2R4F in a puff-by-puff comparison. As illustrated in FIGS.4-6, the control cigarette and the flavor band cigarettes both reducebenzene, acrolein and 1,3-butadiene at similar levels. As such, whenmenthol is provided by the flavor bands, the menthol does notsignificantly deactivate the sorbent in the cigarette, at least aspertains to benzene, acrolein and 1,3-butadiene reduction.

Preferably, menthol in flavor bands in a cigarette has minimal adverseeffects on sorbents in the cigarette and also allows for high levels ofmenthol to be released during smoking. For example, as illustrated inTable 1, menthol levels such a 0.18 mg/cig, 0.51 mg/cig and 1.36 mg/cigcan be placed in flavor bands on an exemplary cigarette having carbonsorbent material in the filter. As a result, 0.021, 0.058 and 0.145mg/puff of menthol can be delivered during smoking with very littlechange in the acrolein, 1,3-butadiene, acetaldehyde or benzene levels infourth puffs of cigarettes with flavor bands (Examples A, B, C) comparedto cigarettes without flavor bands (Control). However, it is noted thatpreferably the flavor bands provide at least about 0.01 mg/puff ofmenthol flavoring, wherein the level of menthol flavoring per puffdepends upon the concentration of menthol within the polyvinyl acetatefilm forming material, as well as the amount of menthol provided, i.e.,the size and number of flavor bands provided.

TABLE 1 Examples A B C Control Menthol/Polyvinyl 8.5/15 19/15 38/15 0/0acetate (mg) Total Cigarette Data Menthol (mg/cig) 0.18 0.51 1.36 0 TPM(mg) 15.4 16.8 19.1 13.9 Puff Count 8.5 8.8 9.4 8.0 MS Menthol/Puff0.021 0.058 0.145 0 (mg/puff) Puff 4 Data vs 2R4F Acrolein (%) 0 0 0 01,3-Butadiene (%) 0 0 1 0 Acetaldehyde (%) 4 1 4 0 Benzene (%) 0 0 0 0No change observed in CO/TPM and NO/TPM ratios

Additionally, the flavor bands can be used as a substitute for oradditive in a seam adhesive used on the wrapper. For example, the filmmay be placed on a seam of a cigarette wrapper to provide adhesion ofthe seam, as well as flavorant within a cigarette.

In an embodiment mentioned above, encapsulated flavorant can be locatedat least in a filter portion of a cigarette. In some embodiments, theencapsulated flavorant may be located in the filter of a cigarette. Forexample, a sorbent and the encapsulated flavorant can be located in afilter portion of the cigarette, wherein the flavorant is downstreamfrom the sorbent.

Various filter constructions may be used to prepare the cigarettes.Exemplary filter structures that can be used for cigarettes include, butare not limited to, a mono filter, a dual filter, a triple filter, asingle or multi-cavity filter, a recessed filter or a free-flow filter.Mono filters typically contain cellulose acetate tow or filter papermaterials. Dual filters typically comprise a cellulose acetate mouthside and a cellulose acetate plug segment. In such dual filters, thesorbent and encapsulated flavorant are preferably located near thesmoking material or tobacco side of a cigarette. The length and pressuredrop of the two segments of the dual filter can be adjusted to provideoptimal adsorption, while maintaining acceptable draw resistance of thecigarette.

Cigarette triple filters can include mouth and smoking material ortobacco side segments, and a middle segment comprising a filter materialor paper. The sorbent and encapsulated flavorant can be provided in themiddle segment. Cavity filters typically include two segments, e.g.,acetate-acetate, acetate-paper or paper-paper, separated by a cavity.The sorbent is preferably provided in the cavity. Recessed filtersinclude an open cavity on the mouth side, and may incorporate sorbentamongst the plug material. The filters may also optionally beventilated, and/or comprise additional sorbents, catalysts, flavorantsor other additives conventionally used in the cigarette filter art.

EXAMPLES

Exemplary flavorants encapsulated by polyvinyl acetate can be formed topredetermined ratios of flavorant to polyvinyl acetate for high flavorreleasing capacity. Desirably, stable composites of flavorant andpolyvinyl acetate are formed with high levels of flavorant to provideefficient flavor-releasing agents. The following examples of compositesof flavorant and polyvinyl acetate provide data regarding flavorantstability in polyvinyl acetate as a function of flavorant concentration.

In preparing the exemplary composites (i.e., encapsulated flavorants),menthol is used for the flavorant and polyvinyl acetate is used toencapsulate the menthol. A process for preparing the encapsulatedflavorant includes: 1) adding 75.5 g ethanol (95%) to 12.5 g polyvinylacetate beads (MW˜500,000); 2) stirring the mixture at room temperaturefor about 2 hours to form a clear solution; 3) adding 7.5, 15.1, 30.1 or15.1 g of menthol solid to form solutions A, B, C, and D respectively;4) stirring the solutions A, B, C and D for about 6-12 hours to formclear solutions; 5) reducing the ethanol content of solution D from 75 gto 62.5 g; and 6) forming films, beads, bars and fibers aftervaporization of the solvent by casting, molding, extruding, grinding,cutting and/or spinning processes.

The stability of menthol releasing capacity of the formed composites canbe tested, where stability is exemplified by the composite retainingmost of its weight with minimal flavor loss over time in an opencontainer under ambient conditions. Instability, on the other hand, isexemplified by loss of weight and a menthol smell.

As shown in Table 2, of the A, B and C composites, C has the highestmenthol starting concentration, B has the second highest, followed by Awith the lowest starting menthol concentration. When the A, B and Ccomposites are made, however, B has higher menthol retention than C orA. It is noted that the starting menthol levels and ending mentholretention levels of Table 2 are compared with respect to the startingsample weight in order to illustrate the effect on menthol retention bythe polyvinyl acetate. By calculating the ending menthol retention withrespect to the starting sample weight, Composites A-D can be comparedfor menthol retention with each other, as well as the control sample ofpure menthol. Thus, Table 2 illustrates a loss of menthol levels forpure menthol with varying higher levels of retention of menthol inComposites A-D compared to the control pure menthol.

TABLE 2 Menthol Content of Menthol/Polyvinyl Acetate Composites StartingEnd. Menthol Menthol Menthol Menthol Retention %/W1 %/W1 Sample %/W0%/W0 Expected Released Composite A 37 38 38 35 Composite B 55 41 46 46Composite C 71 <18 <37 23 Composite D 54 48 51 52 Control (pure 100 <8100 — menthol) W0: Starting sample weight; W1: Ending sample weight.*Unstable samples under ambient conditions with ±2% error due to varyingmoisture content and calculation error.

This is further illustrated in FIG. 7 which compares menthol retentionover time for Composites A, B and C, as well as pure menthol (control),where A and B have similar menthol retention after 20 days and C andpure menthol have lower menthol retentions. The menthol retentionresults of FIG. 7 appear to illustrate that C is not stabilized in thepolyvinyl acetate, perhaps due to its higher starting menthol level,wherein Composite C behaves similarly to the pure menthol in itsretention level over time.

As illustrated in FIG. 8, the reduction of ethanol levels from B to Dappears to allow for an increase in the menthol retention over time. Incontrast, the Control Sample (pure menthol without polyvinyl acetate)has much less menthol retention over time than either B or D, as alsoillustrated in FIG. 7.

The menthol releasing capacity can also be measured in weight % overtime to determine encapsulated flavorant properties. As illustrated inFIG. 9, an encapsulated menthol (Composite B) is compared with purementhol (not encapsulated), where they are each subjected to increasingtemperatures over time (as shown by the temperature line from thelower-left to the upper-right of FIG. 9 with the temperature on theright axis). As illustrated in FIG. 9, using ThermoGravimetric Analysis(TGA), Composite B and the not encapsulated pure menthol appear tomaintain similar menthol retention at temperatures below about 50° C.(as shown in the upper-left portion of FIG. 9), but at temperaturesabove about 50° C., Composite B maintains its weight better than thepure menthol. As also illustrated in FIG. 9, the pure menthol is atabout 0 wt % at below 100° C., while Composite B stays above 0 wt %until around 600° C. Also, Composite B has over 50 wt % reduction attemperatures exceeding 300° C., where Composite B has about an 80 wt %(from 90 wt % to 10 wt %) reduction in weight from about 100° C. toabout 500° C. and shows a gradual release of menthol (steady reductionin weight %) for a temperature range of about 50° C. to about 200° C.Thus, by encapsulating the menthol in Composite B, release over a largerand higher temperature range can be achieved.

Additionally in another example, samples of the Composite C can be agedfor about three months to determine any changes in stability that agingmay cause. As shown below and as illustrated in FIG. 10, the agedComposite C has improved menthol retention compared with “fresh”Composite C, especially for retention over 4 days.

Therefore, menthol can be mixed with polyvinyl acetate at high levelsand can maintain these high menthol levels if aging is used and/orsolvent is reduced in the composite of menthol and polyvinyl acetate.

Variations and modifications of the foregoing will be apparent to thoseskilled in the art. Such variations and modifications are to beconsidered within the purview and scope of the claims appended hereto.

1. A cigarette comprising tobacco, a filter, sorbent, and anencapsulated flavorant comprising a polyvinyl acetate matrix withflavorant bound within the matrix.
 2. The cigarette of claim 1, whereinthe flavorant comprises menthol or vanillin.
 3. The cigarette of claim1, wherein the encapsulated flavorant: (a) is triacetin-free and iswithin the filter downstream from the sorbent; (b) is located on anouter surface of the filter of the cigarette and the sorbent is locatedin a cavity in the filter; (c) is located in a central region of atobacco rod of the cigarette or is distributed throughout a tobacco rodof the cigarette; (d) comprises a flavor band located on a paper wrappersurrounding a tobacco rod of the cigarette; (e) comprises a flavor bandlocated on a paper wrapper surrounding a tobacco rod of the cigaretteand is located on a seam of the paper wrapper and provides adhesion ofthe seam; (f) is temperature sensitive, wherein temperatures greaterthan 100° C. release flavorant into the cigarette, wherein attemperatures below 100° C., a majority of the encapsulated flavorantremains encapsulated; (g) is within the filter and the filter is a monofilter, a dual filter, a triple filter, a mono or multi-cavity filter, arecessed filter or a free-flow filter; and/or (h) is in the form of afiber, film, monolith, bead, powder or granule.
 4. The cigarette ofclaim 1, wherein the sorbent reduces benzene, acrolein and/or 1,3-butadiene levels for each puff when the cigarette is smoked.
 5. Thecigarette of claim 1, wherein the sorbent comprises activated carbon,molecular sieves, zeolites, or combinations thereof in a passageway of atubular free-flow filter component, a material of a free-flow filtercomponent and/or in a void space of the filter.
 6. The cigarette ofclaim 1, wherein the cigarette is a non-traditional cigarette adapted tobe smoked in an electrically heated cigarette smoking system.
 7. Thecigarette of claim 3, wherein the flavor bands are on an inner or anouter surface of the paper wrapper.
 8. The cigarette of claim 3, whereina portion of the menthol flavorant is released from the polyvinylacetate matrix when a portion of the cigarette is at temperaturesbetween 300° C. and 800° C.
 9. The cigarette of claim 2, wherein thementhol flavorant is present in an amount of about 1-90%, 2-70% or10-50% by weight based on 100 parts by weight of the polyvinyl acetate.10. (canceled)
 11. (canceled)
 12. (canceled)
 13. (canceled) 14.(canceled)
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 17. (canceled)
 18. (canceled)19. (canceled)
 20. A cigarette comprising tobacco, a filter, sorbent,and an encapsulated flavorant comprising a polymer matrix with flavorantbound within the matrix, wherein the matrix is one of polyvinylalcohols, poly-acrylates, poly(ethylene) glycols, poly-glycolic acids,pectin, poly-lactic acid, polyesters, polyethylene oxides, or polyepoxides.
 21. The cigarette of claim 20, wherein the flavorant comprisesmenthol or vanillin.
 22. The cigarette of claim 20, wherein theencapsulated flavorant: (a) is triacetin-free and is within the filterdownstream from the sorbent; (b) is located on an outer surface of thefilter of the cigarette and the sorbent is located in a cavity in thefilter; (c) is located in a central region of a tobacco rod of thecigarette or is distributed throughout a tobacco rod of the cigarette;(d) comprises a flavor band located on a paper wrapper surrounding atobacco rod of the cigarette; (e) comprises a flavor band located on apaper wrapper surrounding a tobacco rod of the cigarette and is locatedon a seam of the paper wrapper and provides adhesion of the seam; (f) istemperature sensitive, wherein temperatures greater than 100° C. releaseflavorant into the cigarette, wherein at temperatures below 100° C., amajority of the encapsulated flavorant remains encapsulated; (g) iswithin the filter and the filter is a mono filter, a dual filter, atriple filter, a mono or multi-cavity filter, a recessed filter or afree-flow filter; and/or (h) is in the form of a fiber, film, monolith,bead, powder or granule.
 23. The cigarette of claim 20, wherein thesorbent: (a) reduces benzene, acrolein and/or 1,3-butadiene levels foreach puff when the cigarette is smoked; and/or (b) comprises activatedcarbon, molecular sieves, zeolites, or combinations thereof in apassageway of a tubular free-flow filter component, a material of afree-flow filter component and/or in a void space of the filter.
 24. Thecigarette of claim 20, wherein the cigarette is a non-traditionalcigarette adapted to be smoked in an electrically heated cigarettesmoking system.
 25. The cigarette of claim 22, wherein: (a) the flavorbands are on an inner or an outer surface of the paper wrapper; and/or(b) a portion of the menthol flavorant is released from the matrix whena portion of the cigarette is at temperatures between 300° C. and 800°C.
 26. The cigarette of claim 21, wherein the menthol flavorant ispresent in an amount of about 1-90%, 2-70% or 10-50% by weight based on100 parts by weight of the matrix.
 27. A cigarette comprising tobacco, afilter, sorbent, and an encapsulated flavorant comprising atriacetin-free polyvinyl acetate matrix with flavorant bound within thematrix wherein the flavorant comprises menthol substantially uniformlydistributed throughout the matrix.